Train-signal system



Jan. 11 1927. I E. c. STAFFORD TRAIN SIGNAL SY'l'EM Filed March 25, 1921 #5 SG EQ WU Earl C. Stafford.

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Patented Jan. 11, 1927. v V

UNITED STATES PATENT OFFICE.

EARL C. STAFFORD, OF PHILADELPHIA, PENNSYLVANIA, ASSIG-NOR TO THE UNITED STATES TRAIN SIGNAL COMIANY, F PORTLAND, MAINE, A CORPORATION OF MAINE.

TRAIN-SIGNAL SYSTEM.

Application filed March 25, 1921. Seria1 No. 55,634.

" 57" My said invention relates to an improved mediate the sisser and the pipe 11 leading 55 interlocking train signal system intended to the air brake train pipe. In this way air particularly for use in railway trains. The brake train pipe pressure is built up in the attachment which comprises the main feadevice all the way to aperture 13. I may ture of improvement in my device may be leave the fixture 10 as in my prior applicaused to advantage in connection with the sigtion, merely adding the new attachment 60 naling device shown in the application of above or below the lateral pipe carrying the Benn and Davies No. 380,286, filed May 10, whistle or sisser 14;. Preferably, however, I 1920 and is so shown in the drawings. substitute therefor a bent pipe 15 leading 10 It is an object of my invention to provide down to a central chamber in the body 16 of simple and inexpensive means whereby a the attachment. Pipe 15 is connected by 65 signal may be transmitted from any car screw threads to a plug 17 threaded in one equipped with electro-pneumatic signaling end of body 16 and a passage 15 leads devices of the general type shown in said through the plug to the central chamber. r application to the engine, whether or not beveled ridge 18 surrounds this passage and all the train units are so equipped. has transverse grooves 19 communicating 7 Referring to the accompanying drawings with the chamber. which are made a part hereof and on which A piston 20 in the chamber is loosely consimilar reference characters indicate similar nected to a rod 21 having a collar 22 formii'lg 20 parts, a valve to rest on a seat at 23. The piston Figure 1 is an elevation of a part of a is normally held as shown in Figure 3 so as 7 train of cars with an engine show g my to close the passage 15 and also to close a device in use, lateral passage 24, by means of a spring 25, Figure 2 is a similar view on a larger scale which also holds the valve 22 on its seat 23 showing my attachment as applied to an to close port 26 leading from the signal pipe electro-pneumatic signal. to the outer air. 80 Figure 3 is a section of my attachment, Spring rests at one end in a pocket of Figure 1 is a detail, 7 a plug 27, having threaded engagement with Figure 5 is an enlarged detailed view of body 16, and a pipe 28 threaded in the plug 30 the signal controller, connects the device to another pipe 29 which Figure 6 is an enlarged detailed VI W '1 leads from the train air signal pipe 30. A 85 the valve of Figure 2. valve 31 is located in the connections and In the drawings reference character 10 preferably as shown in Figure 2.

indicates a signaling device of the general I have shown in Figure 1 part of a train 35 character specifically disclosed in my prlor comprising a car 82 equipped with an elecapplication No. 380,151, filed May 10, 1920. tro-pneumatic signal device as described in as Said signal device comprises a signal arm this application, the engine also having a mounted on an arbor 51 having a crank signal 10 thereon. Cords 33 operate the air arm 52 thereon which is connected by means signals of ordinary t n i use i th an of a connecting rod 53 witha pivotally conventional manner, both on the equipped mounted lever 54-. supporting the core 55 of car and on unequippcd cars 34: and 35. as an armature 56 carried by the electromag- The signals are m c remt with onductor net 57. A valve 58 closes a passage 59 when 36 and 37 d these, onduct rs xtend said valve is maintained in elevated position through hose connections 38 of the train ea by means of the core 55 when the electromagair signal pipes as in application No. 380,-

net is energized thus preventing the pas- 286. The conductors cord 39 operates cirloo sage of air from the pipe 11 to and through cuit breaker 40 shown in Fig. 5, the same the pipe 15. r I ,7 as in that application.

This signaling device is connected by The device of Figure 3, when air is admeans of a conduit 11 to the air brake train m tted from the air-brake pipe through pipe pipe 12 and may be identical with the device 11 will operate by the pressure of the air -1 of the prior application, except that the to depress the piston until passage 24 is unaperture 13 of the sisser 14 is in this case covered after which the piston may still smaller than the ports in the deviceintermove but more slowly. As the plston 1s moved the valve 22 is forced 0E its seat and the passage 26 is opened to relieve the pressure in the train air signal pipe, thus producing a signal on the train in the usual manner. Let it be assumed that certain units of the train are equipped with our electro-pneumatic signaling device, as for example, the engine and the second car from the engine as shown at Figure 1. If the units intermediate the equipped units are supplied with the ordinary train air signal pipe found on all passenger, baggage and express cars the conventional signal 60 may be made to operate regardless of whether or not intern'iediate cars have the electro-pneumatic signaling device.

The train should preferably be made up so as to place all equipped cars at the rear, with unequipped cars, it there are any, between the toremost equipped car and the engine. Valves 31 are then turned off on all cars except the one nearest the engine to prevent waste of air and undue lowering of pressure in the signal pipes. The valve 31 on the engine is also turned off, as the electro-magnet of the signal is not energized under these conditions. The switch at the front end of the foremost equipped car, as in application No. 380,286, is closed to close the circuit through all the equipped cars, a switch at the rear of the last car being also closed. Th signaling system is now ready for operation. A pull on the conductors cord 39 will break the circuit at 40 on the equipped car, hence will deenergize the electro-magnets on that and all connected equipped units thus causing the operation of a signal on each equipped car and also operating the ordinary signal now in use on the engine in the usual way through passage 26 and thus operating the signal of hitherto known type on the engine. Because of the slowness of travel of the air in the train air signal pipe and for other reasons it is somewhat impracticable to operate trains of length greater than eight cars, the signaling system in trains of greater length being more or less ineiiicient and unreliable. lVith my device on the other hand any number of equipped cars may be added to the rear ot' a train and because of the electrical feature the release of pressure will always occur on the foremost equipped car. It therefore even as many as 8 or 10 unequipped cars intervene between such foremost car and the engine the ordinary nal pipe on said cars will still cause the operation of the engine air signal with maximum efficiency.

The use of my device in the situation described does not interfere at all with the operation of the ordinary air signal pipe which maybe used as before and will be so used on unequipped cars. In a situation such as that shown in Figure 1, where unequipped cars happen to be located behind the foremost equipped car, the ordinary air signal must of course be used on such unequipped cars, it being operated exactly as heretofore, a pull on a cord giving a signal to the engineer. It is to be noted that in the use of my device on a train such as first described the air may be cut oif at the rear of the combination car, i. e., the foremost equipped car, whereby the expense of keeping up air pressure in the rear cars of the train is done away with. This device as above stated is intended for use during a transition period where some cars will be equipped and some will not be equipped with the electro-pneumatic signaling device. Should a train be made up entirely of cars equipped with the device of this application all. of the valves 31 may be closed and the system will then operate as if they were absent similarly to my application No. 450,195, filed March 7, 1921. No air pressure is then needed in the signal pipe, which serves merely as a conduit for the wires of the train pipe signal.

lVhile I have illustrated and described a preferred form of my invention 1 do not limit myself thereto, as numerous modilicz tions will occur to those skilled in the art. F or instance, under some conditions I might arrange the signal pipe to operate with straight air pressure, the pressure in the signal pipe being augmented on operation of a cord 39, instead of decreasing. The true scope of the invention is shown by the appended claims.

Having thus fully described my said invention, what I claim as new and desire t secure by Letters Patent, is:

1. In a train signaling system a plurality of train units, an air-brake pipe theret'or, one or more of said units being equipped with electropneiunatic signaling means and others of said units not being so equipped. said signaling means con' prising a signal and means connected to the air-brake pipe for operating the signal, connections between the signaling means and the air signal pipe for giving a signal to the engineer on operation of such signaling means and means in each of said connections for disabling the same whereby the action oi the air signal system may be eliminated it all. cars are equipped with electro-pneumatii: signaling means, substantially as set iorth.

2. In a train signaling system for trains; embodying an air brake pipe, an air signal pipe, and an air opera-ted signal on the engine, the combination therewith of an electro-pneumatic signal on the engine, electro-pneumatic signals on one or more cars and means including connections between the air brake pipe, the air signal pipe and the electro-pneumatic signal on the cars for operating the air signal on the engine wheneve-r any of said electro-pneumatic signals on the cars are operated, substantially as set forth.

3. A train signaling system comprising a pneumatically operated signal on the en gine, an air signal pipe extending through the train, means on individual cars of the train for producing a variation of pressure in the air signal pipe to cause operation of said signal, means including a normally closed electric circuit on one or more of said cars controlling said signal-operating means, and means for breaking the circuit, substantially as set forth.

a. A train signaling system comprising a pneumatically operated signal on a car, a connection to a source of air under pressure for operating the signal, means includ ng a' normally closed electric circuit to prevent operation of the signah a connection from the train signal pipe to the atmosphere, a valve in said connection normally closing the same, and pneumatic means for opening the valve concurrently With the operation of: said signal, substantially as set forth.

5. In a train signal system, an air brake pipe, a train signal pipe, a signal for attaclr ment to a train unit, a signal on the engine, means for operating said first-named signal embodying a pipe connecting the signal to the air brake pipe, a valve in said connecting pipe, means for controlling said valve including an electric circuit, a pipe leading from said connecting pipe to the train air signal pipe, and a valve therein controlled by pressure from the air brake pipe and arranged to be opened by the flow of air through the connecting pipe when the valve in said pipe is operated to permit such flow of air and adapted When opened to lower the pressure in the signal pipe for operating the signal on the engine, substantially as set forth.

6. In a train signaling system, a plurality of train units, an air brake pipe therefor. one or more of said units being equipped with electro-pneumatio signaling means and others of said units not being so equipped said signaling means comprising a signal and means connected to the air brake pipe for operating the signal, and connections between the signaling means and the air signal pipe for giving a signal to the engineer on operation of such signaling means, substantially as set forth.

In Witness whereof, I have hereunto set my hand and seal at Vashington, District of Columbia this 16th day of March, A. D. nineteen hundred and twenty-one.

EARL o. STAFFORD. [1,. 5.] 

